Family discourse is any written or spoken communication between members of a family. Aside from this, it is not easy to define because each family has different standards and methods of communicating. In fact, this is part of what makes family discourse so intriguing — linguists want to understand why people communicate differently given similar family makeups.
The discourse present in families is by no means limited only to family topics. Family discourse can include everything from instructions to basic information about what a family member did or intends to do. It also can include data about what the family member wants or desires, or even information about politics, philosophies and conflicts. Any topic a family member wants to introduce into written or spoken communications is fair game.
Family discourse is of interest to linguists because families often are viewed as a microcosm of society as a whole. By studying family discourse, linguists get some clues about what social constructs are dictating the written and spoken communication in the family unit. This is not an entirely perfect art, because families are not confined to one particular region — some cultural mixing happens. It sometimes happens that a study of family discourse provides insight into the culture from which a family came, not the culture in which they currently are located.
Another reason linguists study discourse in families is that psychologists see family as integral to the shaping of individual identity. The way a person communicates with his family members has a huge effect on how he sees himself. By manipulating family discourse, it is theoretically possible to direct how a person develops.
Written and spoken discourse in a family reveals information about the roles each family member has. For instance, if a mother constantly is telling other members what they are good at or giving praise, a linguist might determine that one role the mother fills is "encourager." In the same way, if a husband routinely asks what needs to be done or what has to be finished, a linguist might see the husband as the family "task organizer" or "manager."
Families adapt with their surrounding culture or independently, so family discourse changes over time. A good example is how parents eventually include their children in conversations with increasingly mature content as the children age. The way through which family discourse is presented also changes, with technology often paving the way for modifications. For instance, families now use mobile devices to "keep tabs" on each other, ask for assistance, or keep relationships strong over distance — for better or worse, it is easier for families to engage in less face-to-face interact than in the past.
A caveat to discourse in families is that debate exists regarding what actually constitutes a family. To some people, family refers only to blood relatives, specifically close relatives such as parents or siblings. To other people, family refers to the people with whom a person lives and who provide a sense of love, connection and belonging. This is interesting because it implies that family discourse includes some specific characteristics that should be recognizable compared to other discourse. Identifying these traits is not as easy at it sounds, however, because different families are influenced by very different cultural constructs and thus do not always use language or behave in the same way.